A satellite communications system may have limited resources in terms of available power and spectrum. Such a system usually has a multi-beam antenna or multiple antennas to provide coverage over a large coverage area in a satellite field of view on the earth. The anticipated communications traffic demand across the coverage area is usually unevenly distributed and may even change over time. Providing communication services via satellite requires the allocation of spectral (e.g., frequency/polarization) and associated power resources (for signal amplification) in each of the satellite beams. The total power needed for the available spectral resources is typically lower than the available power that the satellite can provide. A communications satellite typically includes multiple power amplifiers (PAs), each of which can amplify the signals (including user traffic signals) to a subset of beams. PAs are designed to provide linear amplification of incoming signals up to a certain operating point. Operating the PA beyond this point leads to non-linear amplification that results in degradation of the communications signal. Accordingly, the goal of a satellite communications system is to ensure that the PAs operate within the allocated power limit and in the linear amplification region. The spectral resource allocation to different beams should thus account for the power thresholds at the entire satellite level and to ensure that all PAs operate in a linear amplification region. This disclosure is in the context of the use of spectral and power resources required within a Long Term Evolution (LTE) network over satellite. While LTE was designed for use in terrestrial wireless networks, it also has several benefits for deployment over a satellite network. In order to attain these benefits, several adaptations are needed—a primary one being the allocation of spectral resources while taking into account the onboard power and PA constraints.